固硫灰对水泥性能的影响

Effect of CFBC Fly Ash on Properties of Cement

利用XRD、SEM、差热分析和水化热分析等方法研究不同细度和不同掺量固硫灰对水泥物理性能和水泥水化的影响。结果表明,当固硫灰掺量为10%～30%时,水泥安定性、凝结时间均符合国家标准;水泥强度随固硫灰细度的增加而增加,随固硫灰掺量的增加先增加后降低,其最佳掺量为20%;适量的固硫灰,能促进早期C2S、C3S水化,固硫灰细度越细,水泥早期水化速率越快,并影响其早期水化产物的形成;固硫灰掺入后,水泥的水化产物主要为钙矾石、C-S-H、氢氧化钙,并改善了水化产物的热稳定性,同时固硫灰掺量的变化会导致水泥中硫含量的变化,使得C3A水化的最终产物有所不同。

The influence of fineness and contents of CFBC fly ash （CFBA） on physical properties and hydration of ce- ment was researched by means of X-ray diffraction （XRD）, scanning electron microscope （SEM）, differential thermal a- nalysis and hydration heat analysis. The results show that when the mass fraction of CFBA is 10% -30%, the stability and setting time of cement can meet the national standards. The strength of cement increases with increasing of fineness of CFBA, the optimum content of CFBA is obtained, and the optimal content of CFBA in the cement clinker is 20 %. A suitable amount of CFBA can promote the early hydration of C2 S and Ca S. The ground CFBA can improve the early hy- dration rate of cement, and influence the formation of its early hydration products; The hydration products of cement mainly are ettringite, C-S-H, Ca（OH）2 when CFBA is used in cement, and it improves the thermal stability of the hydra- tion products, meanwhile the final hydration product of Ca A is different because the content variation of CFBA can lead to the change of sulfur content in cement.